The abbreviation HRS is used for high resolution spectrography, generally meaning using a spectrograph with a resolving power on the order of 100,000 or higher. A motivation is radial velocity measurements. The abbreviation HDS (high dispersion spectroscopy) is used for the same meaning.
The abbreviation HRS is also used for such instruments, such as the Southern African Large Telescope (SALT)'s high resolution spectrograph or as part of the abbreviation for an instrument such as GHRS (the Goddard High Resolution Spectrograph) on HST. The abbreviation HDS is used for Subaru Telescope's high dispersion spectrograph.
The term low resolution spectrography (LRS, low resolution spectrograph) means the opposite, sometimes meaning anything not HRS, and sometimes assuming a middle ground between.